The general goal of this proposed investigation is to study the synthesis, chemical and biological properties, and reactions of the putative active forms of carcinogenic and/or mutagenic polycyclic aromatic hydrocarbons. In addition, new chemical and spectroscopic methodologies of prospective general applicability will be developed using benzo[a]pyrene (BP) and 7,12-dimethylbenz[a]anthracene (7,12-DMBA) metabolites. Chemical properties of these biologically active arene oxide or diol expoxide metabolites and their in vitro and in vivo reactions with nucleic acids will be investigated in conjunction with the bioorganic mode of action of the parent hydrocarbons and their metabolites. Throughout these bioorganic studies together with biological testings for the carcinogenic and/or activity of synthetic arene oxides and their analogs, pertinent information on the biomechanistic processes associated with these environmental carcinogens will obtained, which will allow us to experimentally evaluate the bay region theory.